With increasingly popular offline payments, the competition among service providers has become increasingly intense. For example, Alipay™, WeChat™, and other service providers have subsidized offline merchants to purchase terminals and payment machines to promote their respective services. However, whether the subsidized machines are deployed at the agreed or expected locations and whether the subsidized machines are actively used, can be verified only through feedbacks from merchants or through field visits. It is difficult to determine whether the feedback information obtained through manual telephone inquiries is reliable, and the labor cost of field visits is high. As a result, it is difficult to learn the actual performance of the payment machines. The understanding of such performance would provide substantial assistance to service providers in making business decisions and outreach plans. Therefore, it is important to obtain credible data.